scholarly journals Structures of the Human SPAK and OSR1 Conserved C-Terminal (CCT) Domains

2021 ◽  
Author(s):  
Karen T Elvers ◽  
Magdalena Lipka-Lloyd ◽  
Rebecca C Trueman ◽  
Benjamin David Bax ◽  
Youcef Mehellou
Keyword(s):  
Oxidative Stress ◽  
Ischemic Stroke ◽  
Protein Kinase ◽  
Drug Design ◽  
Crystal Structures ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Domain Specific ◽  
Wnk Kinases ◽  
And Oxidative Stress

STE20/SPS1-related proline/alanine-rich kinase (SPAK) and Oxidative Stress Responsive 1 (OSR1) kinase are two serine/threonine protein kinase that regulate the function of ion co-transporters through phosphorylation. The highly conserved C-terminal (CCT) domains of SPAK and OSR1 bind to RFx[V/I] peptide sequences from their upstream With No Lysine Kinases (WNKs), facilitating their activation via phosphorylation. Thus, the inhibition of SPAK and OSR1 binding, via their CCT domains, to WNK kinases is a plausible strategy for inhibiting SPAK and OSR1 kinases. To facilitate structure-guided drug design of such inhibitors, we expressed and purified human SPAK and OSR1 CCT domains and solved their crystal structures. We also employed a biophysical strategy and determined the affinity of SPAK and OSR1 CCT domains to an 18-mer peptide derived from WNK4. Together, the crystal structures and affinity data reported herein provide a robust platform to facilitate the design of CCT domain specific small molecule inhibitors of SPAK-activation by WNK kinases, potentially leading to new improved treatments for hypertension and ischemic stroke.

scholarly journals Structure of human tankyrase 1 in complex with small-molecule inhibitors PJ34 and XAV939

2012 ◽  
Vol 68 (2) ◽  
pp. 115-118 ◽  
Author(s):  
Christina A. Kirby ◽  
Atwood Cheung ◽  
Aleem Fazal ◽  
Michael D. Shultz ◽  
Travis Stams
Keyword(s):  
Drug Design ◽  
Crystal Structures ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Donor Site ◽  
Structure Based Drug Design ◽  
Crystallization System ◽  
Tankyrase 1

The crystal structures of tankyrase 1 (TNKS1) in complex with two small-molecule inhibitors, PJ34 and XAV939, both at 2.0 Å resolution, are reported. The structure of TNKS1 in complex with PJ34 reveals two molecules of PJ34 bound in the NAD+donor pocket. One molecule is in the nicotinamide portion of the pocket, as previously observed in other PARP structures, while the second molecule is bound in the adenosine portion of the pocket. Additionally, unlike the unliganded crystallization system, the TNKS1–PJ34 crystallization system has the NAD+donor site accessible to bulk solvent in the crystal, which allows displacement soaking. The TNKS1–PJ34 crystallization system was used to determine the structure of TNKS1 in complex with XAV939. These structures provide a basis for the start of a structure-based drug-design campaign for TNKS1.

Zoning in on Tankyrases: A Brief Review on the Past, Present and Prospective Studies

2020 ◽  
Vol 19 (16) ◽  
pp. 1920-1934
Author(s):  
Xylia Q. Peters ◽  
Thembeka H. Malinga ◽  
Clement Agoni ◽  
Fisayo A. Olotu ◽  
Mahmoud E.S. Soliman
Keyword(s):  
Drug Design ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Design Methods ◽  
Selective Inhibitors ◽  
Computer Aided Drug Design ◽  
Cellular Processes ◽  
Conventional Drug ◽  
Computer Aided ◽  
Tankyrase 1

Background: Tankyrases are known for their multifunctionalities within the poly(ADPribose) polymerases family and playing vital roles in various cellular processes which include the regulation of tumour suppressors. Tankyrases, which exist in two isoforms; Tankyrase 1 and 2, are highly homologous and an integral part of the Wnt β -catenin pathway that becomes overly dysregulated when hijacked by pro-carcinogenic machineries. Methods: In this review, we cover the distinct roles of the Tankyrase isoforms and their involvement in the disease pathogenesis. Also, we provide updates on experimentally and computationally derived antagonists of Tankyrase whilst highlighting the precedence of integrative computer-aided drug design methods towards the discovery of selective inhibitors. Results: Despite the high prospects embedded in the therapeutic targeting and blockade of Tankyrase isoforms, the inability of small molecule inhibitors to achieve selective targeting has remained a major setback, even until date. This explains numerous incessant drug design efforts geared towards the development of highly selective inhibitors of the respective Tankyrase isoforms since they mediate distinct aberrancies in disease progression. Therefore, considering the setbacks of conventional drug design methods, can computer-aided approaches actually save the day? Conclusion: The implementation of computer-aided drug design techniques in Tankyrase research could help complement experimental methods and facilitate ligand/structure-based design and discovery of small molecule inhibitors with enhanced selectivity.

scholarly journals Novel Small-Molecule Inhibitors of Protein Kinase C Epsilon Reduce Ethanol Consumption in Mice

2018 ◽  
Vol 84 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Angelo Blasio ◽  
Jingyi Wang ◽  
Dan Wang ◽  
Florence P. Varodayan ◽  
Matthew B. Pomrenze ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Ethanol Consumption ◽  
Kinase C ◽  
Protein Kinase C Epsilon

Relationship between aldose reductase enzyme and the signaling pathway of protein kinase C in an in vitro diabetic retinopathy model

2020 ◽  
Vol 98 (4) ◽  
pp. 243-251
Author(s):  
Mutlu Sarikaya ◽  
Nuray Yazihan ◽  
Net Daş Evcimen
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Signaling Molecules ◽  
Protein Levels ◽  
Kinase C ◽  
The Relationship ◽  
And Oxidative Stress ◽  
Expression And Activity

Protein kinase C (PKC) and aldose reductase (AR) enzyme activities are increased in diabetes and complications are include retinopathy, nephropathy, and neuropathy. However, the relationship between PKC and AR and the underlying molecular mechanisms is still unclear. We aimed to evaluate the relationship between these two enzymes and clarify the underlying molecular mechanisms by the related signaling molecules. The effects of hyperglycemia and oxidative stress on AR and PKC enzymes and the signaling molecules such as nuclear factor-kappa B (NF-κB), inhibitor kappa B-alpha (IkB-α), total c-Jun, phospho c-Jun, and stress-activated protein kinases (SAPK)/Jun amino-terminal kinases (JNK) were evaluated in human retinal pigment epithelial cells (ARPE-19). AR, PKC protein levels, and related signaling molecules increased with hyperglycemia and oxidative stress. The AR inhibitor sorbinil decreased PKC expression and activity and all signaling molecule protein levels. Increased AR expression during hyperglycemia and oxidative stress was found to be correlated with the increase in PKC expression and activity in both conditions. Decreased expression and activity of PKC and the protein levels of related signaling molecules with the AR inhibitor sorbinil showed that AR enzyme may play a key role in the expression of PKC enzyme and oxidative stress during diabetes.

scholarly journals Cudrania tricuspidata Root Extract Prevents Methylglyoxal-Induced Inflammation and Oxidative Stress via Regulation of the PKC-NOX4 Pathway in Human Kidney Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Donghee Kim ◽  
Jayeon Cheon ◽  
Haelim Yoon ◽  
Hee-Sook Jun
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Antioxidant Enzyme ◽  
Root Extract ◽  
Kidney Cells ◽  
Nuclear Factor ◽  
Ros Production ◽  
Cudrania Tricuspidata ◽  
Pkc Activation ◽  
And Oxidative Stress

Diabetic nephropathy is a microvascular complication induced by diabetes, and methylglyoxal (MGO) is a reactive carbonyl species causing oxidative stress that contributes to the induction of inflammatory response in kidney cells. Cudrania tricuspidata (CT), cultivated in Northeast Asia, has been used as traditional medicine for treating various diseases, including neuritis, liver damage, and cancer. In this study, we determined whether a CT root extract (CTRE) can prevent MGO-induced reactive oxygen species (ROS) production and inflammation and assessed underlying mechanisms using a kidney epithelial cell line, HK-2. We observed that CTRE inhibited MGO-induced ROS production. Additionally, CTRE ameliorated the activation of MGO-induced inflammatory signaling pathways such as p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), and c-JUN N-terminal kinase (JNK). Consistent with these results, expressions of p-nuclear factor-kappa B (NFκB) and inflammatory cytokines, tumor necrosis factor-α, interleukin- (IL-) 1β, and IL-6, were decreased when compared with MGO-only exposed HK-2 cells. CTRE alleviated the MGO-induced decrease in nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and antioxidant enzyme mRNA expressions. MGO induced the expression of NADPH oxidase 4 (NOX4); CTRE pretreatment inhibited this induction. Further studies revealed that the NOX4 expression was inhibited owing to the suppression of MGO-induced protein kinase C (PKC) activation following CTRE treatment. Collectively, our data suggest that CTRE attenuates MGO-induced inflammation and oxidative stress via inhibition of PKC activation and NOX4 expression, as well as upregulating the Nrf2-antioxidant enzyme pathway in HK-2 cells.

scholarly journals A phenolic small molecule inhibitor of RNase L prevents cell death from ADAR1 deficiency

2020 ◽  
Vol 117 (40) ◽  
pp. 24802-24812 ◽  
Author(s):  
Salima Daou ◽  
Manisha Talukdar ◽  
Jinle Tang ◽  
Beihua Dong ◽  
Shuvojit Banerjee ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Small Molecule ◽  
Small Molecule Inhibitors ◽  
Therapeutic Potential ◽  
Protein Kinase Inhibitors ◽  
Response To Treatment ◽  
Rnase L ◽  
Oligoadenylate Synthetase ◽  
In Cells

The oligoadenylate synthetase (OAS)–RNase L system is an IFN-inducible antiviral pathway activated by viral infection. Viral double-stranded (ds) RNA activates OAS isoforms that synthesize the second messenger 2-5A, which binds and activates the pseudokinase-endoribonuclease RNase L. In cells, OAS activation is tamped down by ADAR1, an adenosine deaminase that destabilizes dsRNA. Mutation of ADAR1 is one cause of Aicardi-Goutières syndrome (AGS), an interferonopathy in children. ADAR1 deficiency in human cells can lead to RNase L activation and subsequent cell death. To evaluate RNase L as a possible therapeutic target for AGS, we sought to identify small-molecule inhibitors of RNase L. A 500-compound library of protein kinase inhibitors was screened for modulators of RNase L activity in vitro. We identified ellagic acid (EA) as a hit with 10-fold higher selectivity against RNase L compared with its nearest paralog, IRE1. SAR analysis identified valoneic acid dilactone (VAL) as a superior inhibitor of RNase L, with 100-fold selectivity over IRE1. Mechanism-of-action analysis indicated that EA and VAL do not bind to the pseudokinase domain of RNase L despite acting as ATP competitive inhibitors of the protein kinase CK2. VAL is nontoxic and functional in cells, although with a 1,000-fold decrease in potency, as measured by RNA cleavage activity in response to treatment with dsRNA activator or by rescue of cell lethality resulting from self dsRNA induced by ADAR1 deficiency. These studies lay the foundation for understanding novel modes of regulating RNase L function using small-molecule inhibitors and avenues of therapeutic potential.

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